Benzyl Bromide → (2S,3R,4R,5S,6R)-3,4,5-tris(benzyloxy)-2-methyl-6-(p-tolylthio)tetrahydro-2H-pyran

Participants

Reaction Steps

p-Methylphenyl 2,3,4-Tri-O-acetyl-1-thio-β-L-fucopyranoside (ibid, Brukart, M. D. et al. 1997) (2.5 g, 6.31 mmol) was treated with NaOMe-MeOH. The product was further treated with 85% NaH (463 g, 22.7 mmol) and BnBr (5.8 mL, 37.86 mmol) in DMF (25 mL). After reaction was finished, hexane (30 mL) and water (300 mL) were added into the vigorously stirred solution. The solid product was filtered, washed with water (2×5 mL) and hexane-AcOEt (15:1, 2×5 mL). The crude product was suspended in a hot (70° C.) mixture of AcOEt-Hexane (10:1), and stirred for 10 min. cooled to rt, filtered to gave pure 50 (2.6 g, 76%) as solid: [α]D22 +8° (c, 0.5, CHCl3); HRMS (M+Cs) calcd for C34H36O4SCs 672.1290, found 672.1287.

Provenance & Evidence